Question 553: Asalam alaikum. Is it better to read sura fateha in the third and fourth rakat of salat or is it better to read subhanillahi alhamdolillahi walaillaha ilallah huwallahuakbar 3 times? Surah al-Hamd or tasbihat?
Answer 553: A person offering prayer is at liberty to recite Surat at-l-Hamd and Tasbihat: “Subhanallah, val hamdu lillah, va la illaha illallahu vallahu akbar” (in Arabic) in the third and fourth Rak’ats of obligatory prayers.
It is not far from being preferable for the Imam to recite the Surahs and for the followers to recite Tasbihat. But, for a person offering prayer individually, both are the same.
It is obligatory to recite it in Arabic, and it is sufficient to recite it once, though according to the more cautious opinion it is preferable to recite it three times, and it is better to add Istighfar (Astaghafirullahi Rabbi Wa Atubu Ilayhi) to it.
It is obligatory (for the followers in a Jama’at) to recite Dhikr and Surahs of the Quran quietly, to be more cautious even Bismillah.
It is also permissible to recite Surah al-Hamd in one Rak’at, and Tasbihat Arba’ah in the other, but it is better to recite Tasbihat in both.
 . Imam Khomeini (ra), Tawzih al-Masael (annotated), compiled by Bani Hashemi Khomeini, Sayyid Muhammad Hussain, Vol. 1, Pg. 555, Q 1005, Office of Islamic Publication, Qom, eighth edition, 1424 A.H; Tahrir al-Wasilah of Imam Khomeini (ra), Vol. 1, Rules Concerning Recitation (of Quranic Surahs) and Dhikr.
 . The official Website of the office of Sayyid Sistani (ha), Obligatory acts relating to Namaz » Qir’at.